Non-Fermi Liquids in the Extended Hubbard Model

TL;DR

This paper reviews recent findings on non-Fermi liquid behavior in the extended Hubbard model and related impurity models, highlighting the role of local fluctuations and proposing a local approach strategy.

Contribution

It introduces a new perspective on non-Fermi liquids in correlated systems using a local approach and compares different regimes in the extended Hubbard model.

Findings

Identification of conditions leading to non-Fermi liquids

Insights into spin-charge separation phenomena

Comparison between Fermi liquid and non-Fermi liquid regimes

Abstract

I summarize recent work on non-Fermi liquids within certain generalized Anderson impurity model as well as in the large dimensionality ($D$) limit of the two-band extended Hubbard model. The competition between local charge and spin fluctuations leads either to a Fermi liquid with renormalized quasiparticle excitations, or to non-Fermi liquids with spin-charge separation. These results provide new insights into the phenomenological similarities and differences between different correlated metals. While presenting these results, I outline a general strategy of local approach to non-Fermi liquids in correlated electron systems.